Match each environmental change with its description.
chemicals react with water and oxygen that enter water systems.
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nutrients in excessive amounts enter water systems, causing algal bloom.
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a high concentration of toxic chemicals is present in the bodies of animals at the highest trophic levels.
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Recombinant dna (rdna) creates offspring which are genetically identical to the parent is the process of breeding only organisms with desirable traits involves the removal of the nucleus of a cell combines genes from organisms of different species in a lab

Hormones are chemical molecules produced by endocrine glands. one such endocrine gland is the thyroid gland, which synthesizes the thyroid hormone, which in turn affects the heart muscles. which two statements describe the probable reason for the function of the hormone? the cells in the heart have specific receptors that allow for the intake of hormones. the heart and the endocrine glands have the exact same types of cells. all cells make the same types of hormones. thyroid hormones show their effect on the heart by means of specialized cells. thyroid cells and cardiac cells have different dna.

Which of the following is a true statements about viruses? viruses have no nucleus. viruses are alive. viruses have a cell membrane. all viruses are deadly.